Locking envelope

ABSTRACT

An easily opened, non-adhesively closed, locking-envelope employs on the usual closure flap a tuck-flap that is inserted between a back panel and an overlying lock flap to be held sandwich fashion to maintain the envelope closed.

United States Patent 1191 Bock 1 Sept. 4, 1973 [54] LOCKING ENVELOPE FOREIGN PATENTS OR APPLICATIONS lnvemofl Robert Bock, 817% 723,493 4 1932 France 229/76 North, Seattle, Was 98 09 361,919 12/1906 France 229/76 Filed: Mar. 1971 288,429 4/1928 Great Bntaln 229/76 PP 8,760 Primary ExaminerSamuel B. Rothberg Assistant Examiner-Stephen Marcus 52 US. Cl 229/76, 229/68 R, 229/84 E [51] Int. Cl B65d 27/22 [58] Field of Search 229/76, 68 R, 62, [57] ABSTRACT 229/82 75 An easily opened, non-adhesively closed, lockingenvelope employs on the usual closure flap a tuck-flap [56] References Cited that is inserted between a back panel and an overlying UNITED STATES PATENTS lock flap to be held sandwich fashion to maintain the 180,200 7/1876 Chapman 229/76 envelope closed. 3,236,440 2/1966 Yam Yee 4 Claims, 8 Drawing Figures LOCKING ENVELOPE SUMMARY OF THE INVENTION An envelope comprising substantially equal sized front and back panels, having their common edges joined by closure means, employs a tuck-flap locking arrangement to secure a closure flap in place nonadhesively. On the back panel is an extension which is folded back on the back panel and is secured to function as a lock-flap. The closure flap of the envelope is an extension of the front panel and folds down and lies over the lock-flap. The tuck-flap is an integral extension of the closure flap which is wider than the lockflap. The comers of the tuck-flap are broadly rounded. When the closure flap is being brought into overlying relation to the lock-flap the tuck-flap is very easily in-- troduced behind the free edge of the lock flap. The tuck-flap is then slipped into sandwiching relation between the back panel and the lock flap and the envelope is adequately closed. The lock-flap is preferably not fully attached at its ends to the back panel so that it can give or bow as the tuck-flap is being inserted. The closure flap has a shorter outer edge than the lockflap. And the tuck-flap has a shorter outer edge than the closure flap. During closing while the lock-flap may be bowed in one outward direction as the fingersenter and insert the tuck-flap, the back panel, paper contents, and front panel of the envelope bow oppositely thereby to facilitate closing and locking of the envelope.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are face views of the portions oftwo envelope blanks embodying this locking envelope invention;

FIGS. 3 and 4 are rear face views of the blanks of FIGS. 1 and 2 assembled FIGS. 5 and 6 show the envelope assemblies of FIGS. 3 and 4 in closed and locked condition;

FIG. 7 is a perspective view of a partially assembled envelope of the type shown in FIGS. 2, 4 and 6; and

FIG. 8 is an enlarged detail view in plan of the means whereby the FIG. 7 envelope is end closed and the lock-flap secured.

DESCRIPTION Two closely related forms of the envelope are shown and described in this disclosure. The difference of one with respect the other primarily resides in the means whereby the lock-flap is secured at its ends in juxtaposed relation to the back or rear face of the envelope.

FIGS. 1, 3 and 5 all relate to a first form of envelope embodying the invention herein.

FIGS. 2, 4, 6, 7 and 8 refer to a second form of envelope embodying this invention.

The several elements or parts of the envelope are the rectangular front panel 10, a back panel 12, a lock-flap 14, attached along the upper edge of back panel 12, a closure flap 16 attached to and extending from the upper edge of the front panel 10, and a tuck-flap 18, attached along the outer edge of the closure flap 12. It is preferred that at each end of the front panel there be providedinfolding adhesive tabs 20.

With specificreference to FIGS. 1, 3 and 5, the tab 20 has, as shown in dotted lines and cross-hatching, area 22 to which adhesive is applied on the back face of tab 20 as seen in FIG. 1. When the tab 20 is folded in and back panel 12 is brought into juxtaposition with the front panel l0, the glue-carrying area 22 of tab 20- forms a joinder in conventional envelopemanufacturing technique.

With continued reference to FIGS. 1, 3 and 5, the lock flap of l4 is folded down in overlapping relationship to the upper rear face of back panel 12. Adhesive applied to areas 24, secures the lock flap. Note particularly that adhesive area 24 preferably does not extend the full width of lock flap 14 whereby, when the envelope is assembled, there is an unattached portion of the lock-flap at 26.

Turning now to FIG. 2, it will be noted that between front panel 10 and lock-flap 14, the outer edge 28 of back panel has been relieved or cut away in a tapering mannerserving tonarrow the outer dimension of backpanel 12. In this case the infolding glue tab 21 on front panel 10 has adhesive applied to it in the area 32 defined by'dotted and cross-hatch lines. Note particularly the shape of area 32, as shown in detail in FIG. 8. By reason of the shape of the glue or adhesive area 32 and the relieved'or cutaway edge 28 of this back panel 12, when the latteris brought into juxtaposition with front panel 10 and lock-flap 14 is downfolded and secured, there is a portion 36 of lock-flap 14 which remains unattached. The purpose of the disattachment of portions 26 and 36 will be more fully described later.

It has been found desirable that'in all cases the width of closure flap 16-must beappreciably greater than the width of'lock-flap' 14. This extra width is clearly shown in FIGS. 5 and 6. In that instance-where the envelope length is 7 inches and its widthis 3 7/16 inches, closure flap. 16 is 1 36 inches wide and lbck-flap 14 is 1 k inches wide. Compared, wherelock-flap 14 is 7 inches long, the fold line 17 between closure flap l6 and tuck-flap 18 is desirably and practically 6 inches long. Rounding the comers on a radius of about 2'inches shortens the length of the free edge of tuck-flap 18 and greatly facilitiates its introduction under the free edge of lockflap 14 when the envelope is being closed. The corner radius is appreciably greater than the width of tuck-flap 18.

The sealing or joining of the ends of front panel 10 and rear panel 12in the construction shown in FIG. 3 by means of adhesive area 22, is quite conventional. Thus the joinder of lock-flap 14 to-rear panel 12 requires another adhesive area 24. In contrast, the construction of FIGS. 4, 7 and 8 permit the assembly of panels 10, 12 and lock-flap 14 by the single adhesive area 32. The edge of back panel 12 is indicated by the dotted line in FIG. 8 so designated. By following its course across adhesive area 32 one can see that the back panel edge is adequately secured. Since the end edge of back panel 12 does not entirely cover area 32, that which is uncovered is available to secure the end edge of lock-flap 14 also so indicated in phantom in FIG. 8.

While the foregoing disclosure is specific to two closely related envelope constructions found to be practical and presently preferred, it will be apparent to those skilled in the art that variations in proportions and other modifications will be desirable. All such as by an appropriate and reasonable application of the doctrine of equivalents liberally applied are intended to be covered by the claims herein.

What is Claimed is:

1. An envelope formed of a single sheet of paper or greater dimension to and extending from the upper the like, comprising: edge of said front panel, said closure flap having a a rectangular front panel; width greater than the width of said lock-flap; and a back panel attached along the lower edge of said said closure flap having a trapezoidal-shaped tuck front panel and having dimensions substantially 5 flap attached along its greater dimension to-the equal to the dimensions of the front panel, said outer edge of said closure flap, said tuck-flap being front and back panels being juxtaposed and their insertable under said lock-flap when said closure end edges being adhesively joined together flap is juxtaposed to said lock-flap. whereby to define a pocket; 2. The structure according to claim 1 in which the a lock-flap attached along the upper edge of said side edges of the back panel are cut away to expose back panel, and being down folded from said edge portions of the adhesive joining the juxtaposed end in over-lapping relation to upper rear face of said edges of said front and back panels to the back side of back panel; at the ends of said lock-flap there being the lock-flap at its ends. adhesive means of such extent as only to secure 3. The structure according to claim 1 in which the said lock-flap to adjacent surfaces of said back width of the closure flap is appreciably greater than the panel closely proximate to the attachment of said width of the lock-flap. lock-flap to the upper edge of said back panel, the 4. The structure according to claim 1 in which the lower end corners of said lock-flap being unsecorners of the tuck-flap are rounded on a radius greater cured to said back panel; than the width of the tuck-flap.

a trapezoidal-shaped closure flap attached along its 

1. An envelope formed of a single sheet of paper or the like, comprising: a rectangular front panel; a back panel attached along the lower edge of said front panel and having dimensions substantially equal to the dimensions of the front panel, said front and back panels being juxtaposed and their end edges being adhesively joined together whereby to define a pocket; a lock-flap attached along the upper edge of said back panel, and being down folded from said edge in over-lapping relation to upper rear face of said back panel; at the ends of said lock-flap there being adhesive means of such extent as only to secure said lock-flap to adjacent surfaces of said back panel closely proximate to the attachment of said lock-flap to the upper edge of said back panel, the lower end corners of said lock-flap being unsecured to said back panel; a trapezoidal-shaped closure flap attached along its greater dimension to and extending from the upper edge of said front panel, said closure flap having a width greater than the width of said lock-flap; and said closure flap having a trapezoidal-shaped tuck flap attached along its greater dimension to the outer edge of said closure flap, said tuck-flap being insertable under said lock-flap when said closure flap is juxtaposed to said lock-flap.
 2. The structure according to claim 1 in which the side edges of the back panel are cut away to expose portions of the adhesive joining the juxtaposed end edges of said front and back panels to the back side of the lock-flap at its ends.
 3. The structure according to claim 1 in which the width of the closure flap is appreciably greater than the width of the lock-flap.
 4. The structure according to claim 1 in which the corners of the tuck-flap are rounded on a radius greater than the width of the tuck-flap. 